An unprecedented number of children are being seen in emergency rooms and pediatric intensive care units in the US, with respiratory syncytial virus (RSV) emerging as a key pathogen. Compared to the same time of year in 2018 and 2019, the rate of RSV-associated hospitalizations is already more than 10 times higher for children under one year old and more than 8 times higher across all ages, according to the CDC’s RSV Dashboard.
Though experts expected this surge in respiratory viruses, hospitals are nonetheless overwhelmed. RSV can lead to severe lung inflammation or infection in babies and adults older than 65 years of age. In fact, even prior to COVID-19, data from 2017-2019 suggests that RSV costs an estimated $1.2 billion annually in health care and lost productivity in the US alone.
According to a recent NPR article, current public health recommendations include handwashing, hydration, keeping hands away from the face, disinfecting surfaces, and distancing infants less than one year old from adults who have been recently ill.
On Tuesday, Pfizer announced a maternal RSV vaccine, which when administered during a woman’s pregnancy, should protect infants from developing severe RSV-related symptoms, with more than 81 percent efficacy for the first three months of life and 69 percent efficacy up to the first six months. Pfizer hopes the vaccine will be approved by the FDA by the end of this year.
Since 2021, viruses like RSV have been appearing in the summer rather than in colder “flu” seasons. The increased incidence of severe cases is linked to a decrease in COVID-19 precautions. In addition, some health authorities believe that babies born during the pandemic were not exposed to common viruses and therefore have decreased immunity to circulating respiratory viruses; however, there is also increasing evidence for immune dysregulation from even mild viral infections, such as from the widespread Omicron SARS-CoV-2 variant, which leaves children susceptible to future viral attacks. Further research will be necessary to ascertain the mechanisms underlying the surge in severe pediatric RSV incidence compared to previous years.